The Spanish word 'sexto' meaning 'sixth' comes directly from the Latin word 'sextus', which also meant 'sixth'. This is a straightforward inheritance where both the form and meaning have remained remarkably stable from Latin to Spanish, with only minor phonetic adaptation to Spanish sound patterns.

Some related Spanish words include 'seis' (six), 'sesenta' (sixty), and 'sexteto' (sextet). All these words share the same Latin root related to the number six. While 'sexto' specifically refers to the ordinal number 'sixth', these related words all connect to the concept of 'six' in different ways.

English speakers can easily remember 'sexto' by connecting it to several English words that share the same Latin origin, such as 'sextant' (a navigation instrument marked with a sixth of a circle), 'sextuple' (sixfold), and 'sextet' (a group of six). The prefix 'sex-' meaning 'six' appears in many English words, making it easier to remember that 'sexto' means 'sixth'.